If you think there is only one difference, ask What is the difference? or Is there any difference?
If you think there are likely to be several differences, then use the plural.
I personally am not familiar with "point form." I use "bullets."
I use bullets when I have at least two points that are very similar. They need to be parallel. I would not use bullets for a noun phrase and an adjective phrase.
I'm not sure what you mean by #1. If I am editing the person's writing, I make the comments within the document.
Citations are usually listed in a specific format.
Tables of contents are ... tables. Not bullets.
Rules lend themselves well to bullets, or to being numbers.